DE19810333A1 - Automatic tool positioning arrangement - Google Patents

Abstract

The arrangement or robot has a processing plane (1) with mutually parallel longitudinal guides (2), a U-shaped gate (3,4) raised above the processing plane, a drive unit (7) for longitudinal gate movement, and a tool arm (12) attached to a cross-bearing unit (11) guided in a cross-guide for a carrying beam (4) and in a vertical guide for the tool arm. A second drive unit (10) is used for transverse motion of the cross-bearing unit, and a third drive (13) for vertical movement of the tool arm in the cross-bearing unit and a rotary module unit attached to the tool arm. The rotary module unit has first (15) and second (16) rotary modules with mutually perpendicular axes and a tool (18) carrier (17) on the second rotary module.

Description

The present invention relates to a machine for Posi tioning of a tool, the tool on any Points can be positioned within a processing space. Such machines are often referred to as robots net.

In the industrial sector, automation of Production processes in the last few years above all so-called articulated arm robots and portal robots special Gained meaning. The main areas of application of such Automatic machines are welding, cutting, gluing and other joining machines gears and the automatic handling of workpieces and Assemblies. Often robots are for a very special one Designed for use.

The German patent DE 27 54 436 describes one computer controlled manipulator. The manipulator described has a powered gripper whose position is in is changeable in several directions. The manipulator points to this opens several axes of motion along which linear an shoots are arranged. Because of the Linearan used drives is only a relatively imprecise positioning of the Grei possible. The power transmission along each other in the Angle of movement axes due to the resulting leverage that the manipulator very massive to move even small masses is.  

Different designs of modern articulated robots are for example in a company brochure from Comau S.p.A. shown from 1997. Modern articulated-arm robots up to six axes, which means a lot of free space degrees of safety are made available. Almost all common articulated arm robots have one at the end of the movement chain Wrist, which enables rotary movements around two axes. To use an articulated arm robot within one machining To be able to move to any position is a very large structure of the robot required, because in the unfavorable In the case of the robot's cantilever, the machine has a Workpiece must be guided so that the back of the work piece can be reached with the wrist. Due to the required large dimensions of the articulated arm robot the joints between the individual elements of the robot can absorb large forces and powerful drives be used. With these necessarily stable and large constructions prepares for ensuring a high one Positioning accuracy problems. The maximum with the hand masses to be moved are relatively small.

In European patent EP 0 073 185 there is a Welding machine shown, in which the basic structure of a Portal robot with the advantages of an articulated arm robot was combined. The portal structure is perpendicular by two standing columns formed that the horizontal Bear the beams on these pillars in the vertical direction can be moved. There is a conventional one on the beam Articulated arm robot attached in the horizontal direction can be moved along the bar. On which the machining end facing the articulated arm robot turn a wrist. The disadvantage of the illustrated  Automatic welding machine consists above all in the difficult Controllability of the individual drives, since the respective Movements have to be coordinated. To the machine letting a certain sequence of movements be carried out is in usually complex programming for each individual Drive required. The achievable positioning accuracy of the machine shown is due to the kink used arm robot relatively low.

An improved drive system, which for example for Vending machine can be used is in a company script to the "MoRSE" product line from Amtec Automatisierungs- Mess- und Testtechnologies GmbH from April 1997. These are individual drive modules with are equipped with a so-called local intelligence, so that their control in a simple manner via a serial Bus can be done.

In a company brochure by H.G. Ridder automation rungs-GmbH for the "WARICUT" product range is a CNC high pressure water jet cutting system shown. This cutting system has a portal structure, in which two support columns are movable along longitudinal guides. The two Support columns are connected by a support beam, the one Lateral guide for one essentially perpendicular to the machining provides level tool arm. On which the Machining plane facing end of the tool arm is a Tool holder attached. With such a device is only a tool guide arranged perpendicular to the working plane tion possible, so that for example the change of Cutting angle at which the water jet hits the workpiece hits, is not possible. This device according to the state of the  Technology also enables the use of five axes of motion using a wrist module, creating a better The tool can be adjusted. However in this case the machining room in which the tool can be used, significantly restricted, for example as a significant when tilting the tool Distance between tool and vertical axis of movement results. Because of this distance you have to leave circular trajectories with tool tilted From the vertical axis of motion, the webs are clearly large driving on their radii, which ultimately leads to a reduction the working speed. With such movement orbits is also a full turn (360 °) around the vertical right axis of movement (z-axis) required, leading to conflict leads with the supply lines.

An object of the present invention is that above-mentioned disadvantages of state-of-the-art machines Avoid technology. By the invention, an automat be made available for the positioning of a Tool at any point within a machining room, has a simpler structure and is more controllable.

These and other tasks are performed by an automat solved the claim 1. The machine according to the invention offers the advantage that the tool at any point can be positioned within the processing space without the outer dimensions of the machine the machining room significantly exceed. Unlike most conventional portal robots it is due to the parallel Longitudinal guides on which the portal structure in the longitudinal direction  can be moved, possible, the machine and this move the fastened tool out of the machining area, so that the workpiece located in the machining space or there arranged assembly are easily accessible and for example as recorded by other handling machines and can be transported away. Due to the structure of the Vending machine according to the invention, which in principle one Portal robots can be large on the tool carrier Powers are absorbed. This is also under supports that to provide the movability of the work witness carrier along three perpendicular to each other Space axes (x, y, z) no swivel or articulated joints required are. Power transmission to the longitudinal guides no difficulties. By using more precise Longitudinal guides in combination with drives with high re fetching accuracy (e.g. stepper motors) can the fiction automatic machine with repeatability that are not achieved with conventional articulated arm robots is cash. A particular advantage of the Automa according to the invention ten results from the fact that a Rotary module unit is arranged, which consists of a first torque dul and a second rotary module, which is rotatable on the first Rotary module is attached and its axis of rotation perpendicular to Axis of rotation of the first rotary module extends. One hand articulated module, like almost all other robots is therefore not necessary, which means that the after parts of such modules are omitted. The positioning accurate speed that can be achieved by using the rotary modules can, above the position that can be achieved with wrists kidney accuracy.  

In a first embodiment, the first and the second rotary module arranged so that their axes of rotation are parallel run to the working plane. This version is suitable especially for use on water jet cutters, at which the tool attached to the second rotary module during machining at a desired angle to the machining level can be performed to achieve optimal cutting results to get at the cut edges. Another advantage of Use of rotary modules instead of wrist modules Water jet cutters are such Rotary modules simply manufactured in a waterproof version can be what makes them insensitive to water spray makes. The other drive modules can also be used with this Application can be designed in a waterproof version.

In a second embodiment, the axis of rotation of the first rotary module, however, perpendicular to the working plane, while the axis of rotation of the second rotary module parallel to Processing plane runs. This arrangement of the rotary modules is primarily suitable for use in laser cutting or Laser welding systems, which in most cases it is desired that the laser beam be perpendicular to the bear machining workpiece hits.

In a modified embodiment, the support columns be shortened to a structurally necessary minimum. The desired height of the machining area is then indicated by a solid substructure (e.g. made of granite).

In a modified embodiment of the invention Automat is the second rotary module on the first rotary module attached that the tool attached to the tool holder  arranged axially symmetrical to the axis of rotation of the first rotary module net if the rotation of the second rotary module is zero degrees is. It is also particularly advantageous if this embodiment, the axis of rotation of the first rotary module the (extended) axis of symmetry of the vertical guidance of the Tool arm cuts. With this constructive design it is ensured that the tool immediately before the vertical axis of the tool arm (z-axis) posi is tioned and at this point lower in two directions is rotatable to the vertical axis, the aligned Arrangement with the vertical guide guaranteed in any case remains. This particularly advantageous arrangement allows the desired travels between two positions, the are arranged anywhere within the processing area, can be described by simple mathematical functions. As a result, the control of the individual drives of the machine much easier can be programmed than with previous devices the case is. In addition, this arrangement causes for example when moving the tool along a the respective elliptical path in the processing room Tool at every point of this path before vertical guidance of the tool arm remains positioned so that no conflicts with the necessary supply lines for the tool arise. Although it is in the arrangement according to the invention is a 5-axis machine, are due to this the special arrangement of the two rotary modules Bewegungsab runs executable in devices according to the prior art are only possible with 6-axis machines.

A particularly advantageous embodiment of the present The invention is characterized in that all drive units  and rotary modules are self-sufficient power generation units that have a uniform interface for data exchange and can be controlled via a serial data bus. Such Modules have an integrated control unit, which only the data of the desired movement / position must be carried out and automatically from this data required control signals for the actual drive element generated. By using a serial The data bus for data transmission is reduced effort. The modules are with a uniform Interface for power supply and data transmission equipped. They also have a light weight, which means the design of the machine according to the invention in lightweight construction is made possible. In addition, the machines can go through the modular structure expanded at any time or the modified one Production requirements are adjusted.

An expedient embodiment of the car according to the invention maten has first, second and third drive units, the each consist of a motor module and a bearing module, between which a linear guide runs, which the longitudinal guide, the transverse guide or the vertical guide provides. Preferably, the motor modules and the Storage modules designed cube-shaped. Because of this construct The drive modules and the respective features form a tive feature Guides building units that work with each other in a simple way to be connected to the desired portal structure can. In this way it is possible to invent Provide machines with different sizes that are specially adapted to the respective application. A Another advantage of the modular structure is the quick len interchangeability of individual modules in error or  Maintenance case. In addition to the tax, preferred modules have ersystem also a measuring system, which the performed Bewe conditions recorded so that feedback information in a control loop can flow in.

The desired linear movements are thereby preferred provided that the rotary motion generated in the motor module with a toothed belt running along the linear guide or a spindle drive in the linear movement becomes. The preferred way of moving formation depends on the requirements placed on the Positioning accuracy, the speed and the over supporting forces of the machine. When used For example, positioning of spindle drives Accuracies of ± 0.005 mm per axis can be achieved, from which an accuracy of the machine of approximately ± 0.01 mm results.

A particularly preferred embodiment of the machine is characterized in that the first and the second Rotary module each consist of two cubes facing each other are rotatable. Such rotary modules can be done without difficulty connected with each other and enable a flexible design of the attachment of the tool holder.

In a modified embodiment of the machine is on Tool carrier arranged a force-torque sensor. One On the one hand, this sensor can be used to operate the machine at the factory Measure applied force, the measurement signal obtained if necessary used as an input signal for a control loop can be. On the other hand, the force-torque sensor serves simplified programming of the machine according to the invention. To give the machine a desired sequence of movements  This movement sequence can be followed on a model be, with the force-moment sensor bumps in a contour and body edges can be detected. But it can other seam tracking systems are also used, which is a simplified programming of the desired movements enable trajectory (teach in).

In modified, appropriate embodiments of the Automa ten the tool is a welding machine, a water jet Cutting device, a laser or a gripper. On the tool carrier any other tools can also be attached. This means that a flexible machine is available, which at Changes in the production process for others in a short time Tasks can be converted.

The automat according to the invention can also be used with any other Joining processes are used.

Further advantages, details and further developments of the present invention result from the following Description of advantageous embodiments with reference on the drawing. Show it:

Figure 1 is a perspective view of a automat according to the invention with a rotary module unit in the starting position.

FIG. 2 is a perspective view of the machine from FIG. 1 with the rotary module unit in a first working position;

Figure 3 is a perspective detail view of a tool arm with a rotary module unit attached to it.

Fig. 4 in a side detailed view of the rotary module, with a first rotary module in a rotated position;

Fig. 5 in a side detailed view of the rotary module unit from Fig. 4, wherein a second rotary module is also in a rotated position.

Fig. 1 shows a perspective view of an inventive machine. The machine has a processing level 1 , which can be designed in any way, adapted to the respective task. For example, perforated grid tables are used, on which a workpiece to be machined can be attached. It is also possible that the processing plane has recesses or surveys which are advantageous for the particular application. For example, when executing water jet cutting operations, it is useful to design the processing level in the form of a grid, under which a water collecting trough is positioned, which serves to receive the water jet and at the same time to reduce the energy of this jet.

In the example shown, two parallel longitudinal guides 2 are arranged essentially at the level of the processing plane 1 . In other embodiments, the longitudinal guides 2 can also be positioned laterally, below or above the machining plane if this is advantageous, for example, for accessibility to the workpiece located on the machining plane.

A U-shaped portal structure rises above the processing level 1 and consists of two support columns 3 and a support beam 4 extending between these two support columns. The dimensions of the longitudinal guides 2 and the U-shaped portal structure determine the processing space within which the machine can perform the desired work. The support columns can also be shortened and arranged on a solid base (e.g. made of granite) in order to achieve the desired processing height. The support columns 3 are each attached to a longitudinal guide 2 via a bearing element 5 . On the longitudinal guide 2 , a first drive unit 7 is also arranged, which comprises a motor module 7 a and a bearing module 7 b. A linear guide 8 extends from the motor module 7 a and the bearing module 7 b. The front longitudinal guide 2 in the figure has at each end of the linear guide 8 a bearing module 7 b. The driving force is thus applied in this embodiment only to the longitudinal guide 2 shown in the figure Darge rear. If higher drive forces are required, the second longitudinal guide can also be equipped with an active motor module or a gear is provided (for example a shaft), with the aid of which the driving force generated by a motor module is also transmitted to the second longitudinal guide. About a suitable gear element, for example a toothed belt or a spindle drive, which runs along the linear guide 8 , the driving force generated is transmitted to the bearing element 5 , so that the U-shaped portal structure is driven in the longitudinal direction to move. In the figure, a direction arrow labeled x is shown, which describes the course of this longitudinal direction.

In the same way, the support beam 4 is equipped with a second drive unit 10 , which consists of a motor module 10 a and a bearing module 10 b. A linear guide 8 likewise runs between the motor module 10 a and the bearing module 10 b. On supporting bar 4 by utilizing the linear guide cross bearing unit 11 is arranged, which serves on the one hand the bearing to the supporting beam 4 and on the other hand the storage of a direction perpendicular to the supporting bar 4 tool arm 12th The tool arm 12 is designed in the same way as the support beam 4 and the longitudinal guides 2 and just has a linear guide 8 , which interacts with the cross bearing unit 11 . On the tool arm 12 , a third drive unit 13 with a motor module 13 a and a bearing module 13 b is provided. The second drive unit 10 causes in the manner described with respect to the longitudinal guide 2 a linear movement of the cross bearing unit 11 with the tool arm 12 along a transverse direction, which is illustrated in the figure with a directional arrow y. Again in the same way, the third drive unit 13 causes a vertical movement of the tool arm 12 in the vertical direction with respect to the machining plane 1 , which is illustrated by the direction arrow z drawn in the figure.

It is readily apparent that the individual elements of the U-shaped portal structure in a wide variety Dimensions can be applied. Thanks to the modular The structure of the drive units can be between the motor module and bearing module arranged linear guides also exchanged be so that the machine quickly to changed produc  tion requirements can be adjusted. Because of the modula Different performance classes can also be built of drive modules and transmission variants combine other.

A rotary module unit, which consists of a first rotary module 15 and a second rotary module 16, is fastened to the lower end of the tool arm 12 facing the processing plane 1 . The rotary modules 15 , 16 are in turn composed of two individual modules, namely a fixed module 15 a and 16 a and a movable module 15 b and 16 b. In this embodiment, the axes of rotation of the two rotary modules 15 , 16 are parallel to the machining plane 1 and perpendicular to one another. Since the fixed module of the second rotary module 16 a is attached to the movable module of the first rotary module 15 b, activating the first rotary module 15 causes a circular movement of the second rotary module 16 about the axis of rotation of the first rotary module.

In other embodiments, the first rotary module can be arranged so that its axis of rotation perpendicular to the machining tion level, i.e. parallel or axially symmetrical to that along of the tool arm extending vertical axis. The The axis of rotation of the second rotary module is also in this version tion perpendicular to the axis of rotation of the first rotary module, that is arranged parallel to the working plane. The one with this Arrangement achievable freedom of movement of the second torque dul corresponds to the tool attached to the tool carrier with regard to the freedom of movement of those previously described Embodiment. Even with this 5-axis arrangement you can Trajectories are traversed, as is the case with devices the state of the art only possible through a 6-axis construction  is. The last-mentioned embodiment is suitable especially when used on machines that use a laser as a tool use.

On the movable module of the second rotary module 16 b, a tool holder 17 is attached, which carries a tool 18 . The Akti vation of the second rotary module 16 therefore causes a circular movement of the tool carrier 17 with the tool 18 about the axis of rotation of the second rotary module.

The individual active modules (motor modules and rotary modules) of a type that is both mechanical as well as in terms of control technology are true. The mechanical conformity enables one easy lining up of different modules under one sa tion of additional connecting elements or using simple standardized fasteners. In tax The active modules are from a technical point of view coordinated that they are capable of one serial data bus to receive data and to subsequent Deliver modules. Preferably modules from the Product line "MoRSE" used in the description line are designated in more detail. Of course, others can too active modules are used, insofar as they are described Meet requirements.

Fig. 2 shows a perspective view of the machine according to the invention from FIG. 1, the rotary module unit consisting of the first rotary module 15 and the second rotary module 16 being shown in a first working position. It can be seen that both the movable module of the first rotary module 15 b relative to the fixed module 15 a, and the movable module of the second rotary module 16 b relative to the fixed module 16 a have assumed a rotated position. This results in a position of the tool 18 lying obliquely in the machining space. The tool 18 can be, for example, a water jet cutting device or a welding device. Of course, any other tools can be attached to the machine according to the invention, with which a specific task can be solved in the processing area. A coordinated control of the motor modules and the rotary modules is required so that the tool 18 runs through a movement path corresponding to the work task.

FIG. 3 shows a perspective detailed view of the tool arm 12 , which is guided in the cross bearing unit 11 . To simplify the rest of the portal structure is not shown. The rotary module unit is in turn arranged at the lower end of the tool arm 12 . In this case, a first flange element 20 is laterally attached to the bearing module 13 b, the other end of which is connected to the fixed module 15 a of the first rotary module. The first flange element 20 is designed such that the axis of rotation of the first rotary module 15 again runs parallel to the working plane and perpendicular to the vertical axis of the tool arm 12 . In addition, a lateral offset is achieved, whereby the vertical axis runs through the center of the movable module 15 b of the first rotary module. On the movable module 15 b, a two-th flange element 21 is flanged on the side, which carries the fixed module 16 a of the second rotary module at its other end. Due to the suitable choice of the dimensions of the first and the two th flange elements 20 , 21 and the uniform, cube-like design of the movable modules and the fixed modules it is achieved that the axis of rotation of the first rotary module runs through the center of the movable module 16 b of the second rotary module . Since the tool carrier and the tool arranged thereon are laterally attached to the movable module of the second rotary module 16 b, the tool is in all positions that can be assumed during the working movement, immediately in front of the vertical axis of the tool arm 12 .

Such an arrangement of the two rotary modules acts last Lich like a ball joint, which connects the Tool arm and tool manufactures. Because this ball joint is placed directly in front of the vertical axis (z-axis) the processing space can be used much better than for example when using a wrist module it is possible. In addition, the required travel path is Vertical guidance less than for devices according to the state of the Technology so that the achievable machining speed ten are higher.

Fig. 4 shows a further side view of the arranged at the lower end of the tool arm 12 rotary module, which is already shown in Fig. 3. In this case, the rotary module unit is shown in a state in which the movable module of the first rotary module 15 b is rotated relative to the fixed module 15 a. As a result of this rotation, the movable module of the second rotary module 16 b is pivoted downward and the fixed module 16 a is pivoted upward. The flange elements 20 , 21 are structurally adapted to the movements to be carried out so that, if necessary, rotary movements of 360 ° can also be carried out by the rotary modules.

Fig. 5 shows another side detail view of the rotary module arranged at the lower end of the tool arm 12 unit in a changed movement position. The movable module of the first rotary module 15 b is again shown in a rotated position relative to the fixed module 15 a, as is already shown in FIG. 4. In addition, the movable module of the second rotary module 16 b in the view shown in FIG. 5 has assumed a rotated position relative to the fixed module 16 a.

From these exemplary views it can be seen that by suitable controls for the two rotary modules and the three linear drives belonging to the machine have any desired position tion in the machining area with the tool can.

Claims (18)

1. A machine for positioning a tool ( 18 ), the tool being positionable at any point within a machining space, comprising:

• - a working plane ( 1 );
• - at least two parallel longitudinal guides ( 2 );
• - A U-shaped portal structure, which rises above the processing level, consisting of
• - Two support columns ( 3 ), which are each guided on at least one of the longitudinal guides ( 2 ), and
• - A support beam ( 4 ) which extends between the two support columns and provides a transverse guide;
• - A first drive unit ( 7 ) for a longitudinal movement of the portal structure;
• - A tool arm ( 12 ) equipped with a substantially perpendicular to the machining plane vertical guide, which is connected to a cross bearing unit ( 11 ) which is guided on the one hand in the transverse guide of the support beam ( 4 ) and on the other hand in the vertical guide of the tool arm;
• - A second drive unit ( 10 ) for the transverse movement of the cross bearing unit ( 11 ) with the tool arm ( 12 );
• - A third drive unit ( 13 ) for the vertical movement of the tool arm ( 12 ) in the cross bearing unit ( 11 );
• - A rotary module unit, which is attached to the end of the tool arm ( 12 ) facing the machining plane, consisting of
• - A first rotary module ( 15 ) and
• - A second rotary module ( 16 ) which is rotatably attached to the first rotary module, wherein the axis of rotation of the second rotary module is perpendicular to the axis of rotation of the first rotary module; and
• - A tool carrier ( 17 ) which is rotatably attached to the second Drehmo module ( 16 ) and carries the tool ( 18 ).

2. Automat according to claim 1, wherein the second rotary module ( 16 ) is attached to the first rotary module ( 15 ) in such a way that the tool ( 18 ) attached to the tool carrier ( 17 ) is arranged axially symmetrically to the axis of rotation of the first rotary module when the rotation of the second rotary module is 0 °. 3. Automat according to claim 1 or 2, characterized in that the axes of rotation of the first ( 15 ) and the second Drehmo module ( 16 ) run parallel to the processing plane ( 1 ). 4. Automat according to claim 3, characterized in that the axis of rotation of the first rotary module ( 15 ) intersects the axis of symmetry of the vertical guide of the tool arm ( 12 ). 5. Automat according to claim 1 or 2, characterized in that the axis of rotation of the first rotary module ( 15 ) extends perpendicular to the working plane ( 1 ), and that the axis of rotation of the second rotating module ( 16 ) runs parallel to the working plane. 6. Machine according to one of claims 1 to 5, characterized records that all drive units and rotary modules self-sufficient power generation units, which are a uniform own interface for data exchange and via a serial data bus can be controlled.   7. Automatic machine according to one of claims 1 to 6, characterized in that the first, second and third drive unit each from a motor module ( 7 a, 10 a, 13 a) and a bearing module ( 7 b, 10 b, 13 b) exist between which a linear guide ( 8 ) runs, which provides the longitudinal guide or the transverse guide or the vertical guide. 8. Automatic machine according to claim 7, characterized in that motor modules ( 7 a, 10 a, 13 a) and bearing modules ( 7 b, 10 b, 13 b) are cube-shaped. 9. Automatic machine according to claim 7 or 8, characterized in that the rotary movement generated in the motor module ( 7 a, 10 a, 13 a) is converted into a linear movement with a toothed belt running along the linear guide ( 8 ). 10. Automatic machine according to claim 7 or 8, characterized in that the rotary motion generated in the motor module ( 7 a, 10 a, 13 a) is implemented with a linear drive arranged along the linear guide ( 8 ) in the linear movement. 11. Machine according to one of claims 1 to 10, characterized in that the first ( 15 ) and second rotary module ( 16 ) each consist of two cubes ( 15 a, 15 b; 16 a, 16 b) best, which are rotatable relative to each other . 12. Automat according to one of claims 8 to 11, characterized in that connecting elements ( 20 , 21 ) can be fastened to the free cube surfaces of the motor, bearing or rotary modules. 13. Automatic machine according to one of claims 1 to 12, characterized characterized in that a joining seam track on the tool carrier is arranged. 14. Vending machine according to claim 13, characterized in that the Seam tracking system is a force-moment sensor. 15. Automatic machine according to one of claims 1 to 14, characterized in that the support columns ( 3 ) are shortened to a constructively necessary dimension and are arranged on a fixed substructure which rises between the processing plane ( 1 ) and longitudinal guides ( 2 ) . 16. Automatic machine according to one of claims 1 to 15, characterized in that the tool ( 18 ) is a welding device. 17. Automatic machine according to one of claims 1 to 15, characterized in that the tool ( 18 ) is a water jet cutting device. 18. Automatic machine according to one of claims 1 to 15, characterized in that the tool ( 18 ) is a laser. 19. Automatic machine according to one of claims 1 to 15, characterized in that the tool ( 18 ) is a gripper.